Short wave beam transmitter



Nov. 7, 1933. w LUDEMA 1,934,078

' SHORT WAVE BEAM TRANSMITTER Filed May 12, 1931 INVENTOR WERNER LUDENIA ATTORNEY Patented Nov. 7, 1933 1,934,058 snon'r WAVE BEAM, TRANS ITTER 1' WernerLudenia fierlin, Germany, assignor to'a: h I

Telefunken Gesellschaft fur. Drahtlose Telegraphic in. bill Berlin, Germany, a corpora- 5 I tion of Germany Application'May 1 2, 1931, SerialN0. 536,713, 7 ,5,.

' and in Germany January 1 5, 1930 r 4 Claims.

7 The present invention relates to' beam transmittersand involves a new and improvedmethod of and means for producing andradiating' beams of energy which are characteristic of the path over which they travel.

The novel features of my invention have been pointed out with particularity in the claims appended hereto. a The nature of the invention, the method of operation thereof, and the arrangements" by which the invention may'beflcarried out, have been described in detail in the specification and illustrated in the annexed'drawing, in which:

Figure l is a curve illustrating the radiation which it is desired to obtainywhile, f Figures 2, 3, 4, and-5 illustrate diagrammatically arrangements whereby the present invention is carried out. i

'Io obtain a sharply bounded directional. beam it is advantageous to have recourse to a'diff erential arrangement of the type disclosed by Kiebitz. The same consists in that two not particularly sharp beams or conesof radiations are radiated off 'adjacently so that the well-known diagram shown in Figure 1 is obtained. :Curve I denotes the radiation diagram pertaining to the first beam, while curve II is the diagram corresponding to the second beam. Now, both of these beams or pencils are sdpositio'ned adjacent to each other (juxtaposed) that their diagrams cometo intersect at the steepest points. The transmitters belonging to beams I and 11 trans- 'mit'signals, which, for the same amplitude, re-

sult in a permanent dash or line, say, a and n. Hence, a receiver equipment would receive a permanent dash at point P of Figure 1, whereas in point P1 there would be recorded predominantly the signal corresponding to beam I, and at point P2 the signal corresponding to beam II. This arrangement offers besides certain other drawbacks which consist in that the energies of the transmitters corresponding to the two beams must be absolutely alike in size and absolutely constant. However, these conditions are nonfulfillable in practice, and the result is that considerable errors in directive action of the beam are caused.

In order to insure as perfect as possible a symmetry, applicant proposes to utilize only one exciter in the focus of a concave mirror, and to cause the same to oscillate conjointly with the exciter about an angle a, the plan being to cause the mirror or reflector to stay in the beam I for a relatively short while, andin the beam II for a relatively long time. If the receiver outfit comdiifer ential method using two transm itters is that itis impossibletomaintain both transmitters constantin relation to each other in such a way that equality of the diagram'curves orgraphs of Figure l willbe' secured. Upon orieofthese curves becoming'distorted the point P as afconsequence will be displaced towards the right" or towards the left hand side, depending on which one is distorted. ,This results in inaccuracies in the pointingpharacteristics of'the receiver.

.. A further idea underlying this invention isto utilize just one transmitter so'that by turning or by rocking (oscillating) the diagram Land the diagram II are alternately radiated oil. This :insures that the curves I'and II are 1 representative of currents of like amplitude and nature. end, may be attained by" the use of an exciter generating ultra-short HertZian waves and mounted in the focus of a'l-Iertzian reflector so that. a sharply defined beam is produced whose This.

diagram'correspondsto curve I or; curve II in Figure 1..- Means is provided whereby when the transmitter reflector is in a position so that its radiation diagram coincides with curve I it"will stayin this position only a very brief time measured bythe length of a dot and thenturn exoiter is automatically disconnected, whereupon the reflector oscillates back into its initial position, and during this motion of the, system the eXciter-is again disconnected. One thus obtains 'ing the change from curve I into curve II the the same picture or impression as above in a receiver outfit.

Figure 3 illustrates an embodiment of the idea by way of example. Referring to the drawing, S is the transmitter reflector, E the exciter which is rigidly united with the reflector to form an integral system. 'D is the source ofcurrent which is alternately connected by way of contacts K1 and K2 to the exciter while the system comprising the reflector and the exciter oscillates about the angle a. While the reflector S maybe oscillated in any manner, one means of oscillating the reflector S and exciter E has been given by way of example. A wheel F havingcam surface 1 representative' of the dashes and cam surfaces 2 S and transmitter E through an arc.

proper rotation speed'in any manner, as, for example, by the shaft of source D. A lever 3 fixed at 4 cooperates with a link 5 connected to a member 6 integral with reflector S to oscillatethe reflector The lever B is biased for continued contact with F by. a spring 8. The length of the lever system issuch as to swing S through an angle@. 7 The cam surfaces 1 and 2 may be in any sequence desired to send any code letter or signal; The raised portions and depressions are such that the'lever 3 oscillates about its pivot 4 sufliciently to swing S and/or E through the desired arc and to maintain said elements at the ends of the arc the desired time interval. r V

In a modification of the invention the identical result is obtainable if exciter and reflector are not caused to oscillate simultaneously, but by that either the ex'citer is mounted stationary while only the reflector is'caused to oscillate, or vice versa. Especially the latter arrangement may be of great advantage in actual practice, e. g., when it is necessary to "provide very large reflectors where'ultra-short Hertzian waves aredealt with. It is then unnecessary to setthe reflector being I of great weight into motion, indeed, only the 'exciter is oscillated, but the volume and weight of the latter may be kept inside reasonable limits.

Figure 4. is a diagrammatical' view of an arrangement of this kind. S is the stationary re-- radiator, etc.) about the focus.

flector, E is the exciter'adapted to oscillate around the focus and through the angle a. If E isin the 1 position marked 1, it radiates off the diagram I; J but when it is in the position 2, its radiation corresponds to diagram II. Hence, there is obwithout reflector S1, should oscillate around the focus under exactly symmetric conditions. On

the contrary, the value (1/2 may be'locatedalso outside the focal line, though for economical reasons, it would not be advisable usually to depart too, much from the focus. a v The transmitter at E in this modification may representative of the dots may be driven at the" be energized in the same manner as the transmitter of Figure 3 while the transmitter E may be oscillated through the required arc by an arrangement as shown in Figure 3.

Disturbing or undesirable curves are obtained system is in positions 1 or 2 the rays will no longer be acted upon by Z. When using an exciter for ultra-short waves, recourse "may be had to a metallic rod of around 2 length. By adjusting the distance ZE the conditions of compensation can be very nicelyadjusted.

Having thus described my invention "and the H operation thereof, what I claim is:

l. A beam transmitter adapted to, mark out a course by emitting characteristic signals along each outer boundary of said course comprising,

an oscillation generating system, a directive radiating system connected therewith, means to oscillate one of said systems through a predetermined are, means for maintaining said oscillated system stationary at each end of said are for predetermined'time periods, and means for rendering one of said systems operative during the time said oscillated system is maintainedstationary at each end of the arc of oscillation.

2. An arrangement as. recited in claim 1 including means for rendering one of said systems inoperative during the movement of the oscillated system between the ends of said are of oscillation.

3. An arrangement as recited in claim 1 including means for maintaining said oscillated system stationaryflateach end of the are through which it is oscillated different predetermined time intervals. Y

4. A course indicating device comprising a high frequency, generator, a'reflector, means to oscillate said reflector and' said generator through a predetermined arc, means for maintaining said Ill] generator and said reflector stationary at each end of their *are of oscillation, and'means for rendering said generator operative during the time it is stationary.

WERNER LUDENIA. 

